Experts are trying to figure out what a fossil dubbed “Godzillus” used to be. The 150-pound fossil recovered last year in northern Kentucky is more than 6 feet long and 3 feet wide. To the untrained eye, it looks like a bunch of rocks or a concrete blob. Experts are trying to determine whether it was an animal, mineral or a form of plant life from a time when the Cincinnati region was underwater.

Scientists at a Geological Society of America meeting viewed it Tuesday at the Dayton Convention Center in Ohio. Scientists say the fossil is 450 million years old. University of Cincinnati geologist Carl Brett said it’s the largest fossil ever extracted from that era in the Cincinnati region.

“This is the ultimate cold case,” said Ron Fine, the Dayton, Ohio, amateur paleontologist who spotted the fossil on a hillside last year and gave it its name. “Like Godzilla, it’s a primordial beast that found its way to the modern era… Most fossils around here are small, the size of your thumbnail or your thumb. This thing’s huge.” He said it could be an early form of seaweed or kelp.

“This one has us stumped,” said David Meyer, another UC geology professor. Meyer, who wrote a book called “A Sea Without Fish” about the era, said the fossil has intricate patterns that remind him of “goose flesh. Some of its surface also looks like scales. But this thing is not boney. It is not a fish.”

He guesses it could have been something like a sponge: “Cincinnati was covered by a sea, 100 to 200 feet deep,” Meyer said. “Primitive shellfish lived in it. But no fish.”

Do you think this fossil could be a remarkable find? Feel free to share your speculations below!